Swedish patent application No. 7512817-3 describes a mobile forest cut machine which includes a feeder device that is pivotal between a horizontal operating position and a substantially vertical operating position. However, the construction is such that the feeder device is incapable of being altered during actual operation and that pivoting cannot be performed unless the outlet pipe and the ejector hood are pivoted to an equivalent extent. Moreover, the forest cut machine is useful only for forest material that can be fed in with a regular direction, i.e. the pieces of material such as branches, limbs and trunks are substantially directed regularly in the direction of feeding.
Swedish patent application No. 8003185-9 describes a mobile chipper which is provided with a special device comprising a cutter drum with cam-like cut strips which cooperate with a complementary counter member in order to disintegrate branches and other parts of trees which turn across the direction of feeding after the actual chipping has been performed in a chipper rotor. However, such a device requires more space for the chipper as well as extra bearings and drive mechanisms for the special device. Swedish patent specification No. 163710 describes a wood chipper with a chipper rotor housing which is stationary with respect to a chipper rotor rotatably journalled therein.